Mobile data usage problem

I currently have a pre-pay contract and I only use data for wassap and occasionally maps, and momentary visits to a website or iTunes to get it to play a tune. In other words, very little usage out and about. However…

I noticed I was losing my credit quickly so I turned on mobile data statistics, to see if this would explain what’s going on.

How can I prevent these applications etc using mobile data? I don’t even appear to have Siri on my phone, so that’s weird too.

Or is it that I have made things worse by turning on statistics?! Is that what’s using my data up?!!

This is the report:

Apple ID Services

24.4 KB

DNS Services

104 KB

Game Center

1.42 KB

HomeKit

13.5 KB

iCloud

27.2 KB

iTunes Accounts

56.6 KB

Mapping Services

5.67 KB

Media Services

21.7 KB

Networking

27.7 KB

Push Notifications

125 KB

Screen Time

128 KB

Siri

9.17 KB

Software Updates

44.0 KB

Time & Location

151 KB